Technical Field
The disclosure relates to a laser ranging calibration method and an apparatus using the same, more particularly to a calibration method applied to a line laser ranging task, and to an apparatus using the same.
Related Art
Laser ranging is a high precision measurement method and can be applied to many fields. One of the laser ranging methods is using a line laser generating device and an image capturing device to measure a distance to an object under test according to the fixed relative position relationship between the two devices.
A line laser as a linear correlation distribution light source operates based on two variables. When the value of the variable X changes, the value of the variable Y also changes in response. The variable X indicates the width or thickness of the image of light of the light source on the object under test, the variable Y indicates the length or breadth (known as beam angle) of light of the light source passing through one or more lenses or a certain medium, and the variable Z indicates an energy distribution of light of the light source. X and Y have a property of linear distribution therebetween, X and Z have a property of linear distribution therebetween, and Y and Z have a property of linear distribution as well as a property of non-linear distribution therebetween. The property of non-linear distribution can become linear by engineering methods. One of the engineering methods includes adjusting one or more lenses and the pipe diameter of one or more copper tubes in the inner structure of the line laser. Therefore, all those light sources which fit in this correlation distribution are called liner lasers.
However, for a range finding device using a line laser, the relative positions of the line laser generating device and the image capturing device are actually unsteady because of some outer environment facts as time goes by. Although the relative positions only shift a bit, this shifting may cause great errors to the range finding result. Therefore, it is required to calibrate such shifting.